The present invention pertains generally to folding furniture and, more specifically to tables having legs that fold compactly underneath the tabletop. In particular, the invention concerns an folding apparatus for extending and retracting the legs and a latch mechanism for locking the legs in position.
Folding tables are widely used and derive their primary benefit from the relative ease with which they can be handled and stored when in the folded condition. One typical folding table leg is described in the patent to Weagle, U.S. Pat. No. 3,695,567. Folding tables of this type do not include a cross brace that provides fore and aft support for the table leg. Another difficulty with folding table designs such as the configuration shown in the weagle patent is that the folded legs do not provide a uniform surface on which other folded tables may be stacked because the legs overlap each other.
An alternative design is a trestle-type table, such as the folding table shown in the patents to Burr, U.S. Pat. Nos. 3,818,844 and 4,444,124. In these tables, the vertical legs do not overlap each other; however, like the weagle device, the folded legs themselves provide the stacking surface for other folded tables. An additional difficulty associated with trestle-type tables is that they are often difficult to fold and handle once folded.
In U.S. Pat. No. 4,838,180, owned by the assignee of this invention, the present inventor sought to overcome many of the disadvantages of prior folding tables. This '180 patent describes a folding table that allows the table legs to be compactly folded underneath the tabletop, while still providing a uniform surface on which other tables may be stacked. One benefit of the folding table leg apparatus shown in the '180 patent is that the stacked tables are not supported on the folded legs, but rather on upright flanges forming part of the folding leg apparatus.
Certain details of the folding table leg apparatus of the '180 patent are depicted in FIG. 1. As shown in this figure, the folding leg apparatus 10 includes a top plate 11 that is mounted to the underside of a tabletop. The top plate 11 includes opposite side flanges 12 that project perpendicularly outward from the top plate 11. Rubber pads 14 are mounted at the edges of the side flanges 12 to provide a scratch resistant surface upon which a tabletop may be supported.
The folding leg apparatus 10 of this prior device includes a single tubular vertical leg 15. As shown in more detail in the '180 patent, the vertical leg 15 terminates in a base or foot that is configured to support the table on the floor. A pair of support brackets 20 are each mounted to the top plate 11 at opposite sides of the vertical leg 15. The support brackets provide an attachment or pivot point for a pair of brace links 25. The brace links 25 are pivotally connected at one end to the support bracket 20 and at the other end to the vertical leg 15 by way of a lower pivot rod 28 that passes through the tubular leg. The vertical leg 15 is also supported by an upper pivot rod 35 that spans substantially across the width of the top plate 11. The upper pivot rod 28 is pivotally connected to the side flanges 12 by way of opposite swivel brackets 47. Thus, the brace links 25 and swivel brackets 47 provide a mechanical linkage for controlled movement of the vertical leg 15 between its folded and its extended positions.
In a further aspect of this prior apparatus, a pair of release brackets 40 are provided for positively locking the upper pivot rod 35 in place when the vertical leg 15 is in its extended position. Each of the release brackets includes a lever arm 41 and an actuator plate that is manually depressed to release the upper pivot rod. A torsion spring 44 provides a positive torque to each lever arm 41 to keep it in its locked position when the release brackets 40 are engaged to the upper pivot rod. In this manner, the folding leg apparatus 10 of the '180 patent provides a positive locking mechanism to hold the vertical leg in its extended position. Likewise, the release brackets 40 provide an easy way to release the upper pivot rod so that the vertical leg can be rotated and pivoted to its stowed position. Greater detail concerning the folding leg apparatus 10 of this prior device can be found in the specification of the '180 patent, which description is incorporated herein by reference.
While the folding leg apparatus 10 of the '180 patent represents a significant improvement over prior folding leg apparatus, certain difficulties still remain. One particular problem is that the release brackets 40 are oriented so that they can be accidentally actuated under the table. For example, a person sitting at a conference table could accidentally contact one or both of the release brackets with their leg.
Another difficulty is that the direction of movement of the table leg when the release brackets are actuated can create the risk that the operator's fingers will get pinched in the folding mechanism. There is therefore a need for improvements to these various folding table leg apparatus that retains beneficial features that allow the apparatus to be easily folded and readily stowed. The need encompasses providing a folding table leg apparatus that stows the leg in such a manner as to permit stacking of folded tables.
Moreover, none of the prior folding leg apparatus is readily adapted to dual upright legs. The device in the '180 patent accommodates a single post leg. An additional detriment of some prior devices is that they require manipulation of two release levers to actuate the folding mechanism. While this detriment is of little concern for a single post leg, it is compounded with a dual upright leg that spans a width that is too difficult for the operator to manipulate.